From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: + samples-hw_breakpoint-drop-use-of-kallsyms_lookup_name.patch added to -mm tree Date: Mon, 24 Feb 2020 14:31:01 -0800 Message-ID: <20200224223101.-rRHDWmp3%akpm@linux-foundation.org> References: <20200203173311.6269a8be06a05e5a4aa08a93@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:36116 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726651AbgBXWbD (ORCPT ); Mon, 24 Feb 2020 17:31:03 -0500 In-Reply-To: <20200203173311.6269a8be06a05e5a4aa08a93@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: ast@kernel.org, frederic@kernel.org, gregkh@linuxfoundation.org, hch@lst.de, mhiramat@kernel.org, mm-commits@vger.kernel.org, prasad@linux.vnet.ibm.com, qperret@google.com, tglx@linutronix.de, will@kernel.org The patch titled Subject: samples/hw_breakpoint: drop use of kallsyms_lookup_name() has been added to the -mm tree. Its filename is samples-hw_breakpoint-drop-use-of-kallsyms_lookup_name.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/samples-hw_breakpoint-drop-use-of-kallsyms_lookup_name.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/samples-hw_breakpoint-drop-use-of-kallsyms_lookup_name.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Will Deacon Subject: samples/hw_breakpoint: drop use of kallsyms_lookup_name() The 'data_breakpoint' test code is the only modular user of kallsyms_lookup_name(), which was exported as part of fixing the test in f60d24d2ad04 ("hw-breakpoints: Fix broken hw-breakpoint sample module"). In preparation for un-exporting this symbol, switch the test over to using __symbol_get(), which can be used to place breakpoints on exported symbols. Link: http://lkml.kernel.org/r/20200221114404.14641-3-will@kernel.org Signed-off-by: Will Deacon Reviewed-by: Christoph Hellwig Reviewed-by: Masami Hiramatsu Cc: K.Prasad Cc: Thomas Gleixner Cc: Greg Kroah-Hartman Cc: Frederic Weisbecker Cc: Quentin Perret Cc: Alexei Starovoitov Signed-off-by: Andrew Morton --- samples/hw_breakpoint/data_breakpoint.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/samples/hw_breakpoint/data_breakpoint.c~samples-hw_breakpoint-drop-use-of-kallsyms_lookup_name +++ a/samples/hw_breakpoint/data_breakpoint.c @@ -23,7 +23,7 @@ struct perf_event * __percpu *sample_hbp; -static char ksym_name[KSYM_NAME_LEN] = "pid_max"; +static char ksym_name[KSYM_NAME_LEN] = "jiffies"; module_param_string(ksym, ksym_name, KSYM_NAME_LEN, S_IRUGO); MODULE_PARM_DESC(ksym, "Kernel symbol to monitor; this module will report any" " write operations on the kernel symbol"); @@ -41,9 +41,13 @@ static int __init hw_break_module_init(v { int ret; struct perf_event_attr attr; + void *addr = __symbol_get(ksym_name); + + if (!addr) + return -ENXIO; hw_breakpoint_init(&attr); - attr.bp_addr = kallsyms_lookup_name(ksym_name); + attr.bp_addr = (unsigned long)addr; attr.bp_len = HW_BREAKPOINT_LEN_4; attr.bp_type = HW_BREAKPOINT_W; @@ -66,6 +70,7 @@ fail: static void __exit hw_break_module_exit(void) { unregister_wide_hw_breakpoint(sample_hbp); + symbol_put(ksym_name); printk(KERN_INFO "HW Breakpoint for %s write uninstalled\n", ksym_name); } _ Patches currently in -mm which might be from will@kernel.org are samples-hw_breakpoint-drop-hw_breakpoint_r-when-reporting-writes.patch samples-hw_breakpoint-drop-use-of-kallsyms_lookup_name.patch kallsyms-unexport-kallsyms_lookup_name-and-kallsyms_on_each_symbol.patch